You can supply more than one -n option to synchronize more than one synchronization publication.

There are two ways to use -n to synchronize multiple publications:

Specify -n pub1,pub2,pub3 to upload pub1, pub2, and pub3 in one upload followed by one download.

In this case, if you have set extended options on the publications or subscriptions, only the options set on the first publication
in the list and its subscription are used. Extended options set on subsequent publications and subscriptions are ignored.

When successive synchronizations occur very quickly, such as when you specify -n pub1 -n pub2, dbmlsync could start processing a synchronization when the server is still processing the previous synchronization. In this
case, the second synchronization fails with an error indicating that concurrent synchronizations are not allowed. If you run
into this situation, you can define an sp_hook_dbmlsync_delay stored procedure to create a delay before each synchronization.
Usually a few seconds to a minute is a enough delay.